Left hand side of ISPConfig admin panel blank

I haven't visited the admin panel in a while and just noticed that the left hand side of the admin panel does not show the menus (websites etc) any more. Just upgraded to 2.2.37 - but noticed it prior to upgrading - so it was NOT the upgrade. Maybe something simple I'm overlooking? Any ideas? Not showing for ISP Manager, DNS Manager etc.

I don't think it is an ISPConfig issue. (In fact is NOT an ISPConfig issue) I connected to the admin panel from another computer in my LAN and it works fine. It also works fine from a windows XP virtual terminal on my machine. Also works fine from IE4linux on my machine.

Must be something in Firefox on my machine - I cleared cache, cookies & SSL certs - same thing.

Not a big deal since I can access from everywhere else - Just a challenge for me to make it work.

I installed Firefox 4.0b8pre and now I can access the ISPConfig admin panel just fine. (Problem still exists with Firefox 3.6.10 & .12 (Fixed - see below))

SOLUTION - Should it happen to someone else - I noticed that when I installed Firefox 4.x, it informed me that my add-ons might not work with 4.x - so all were disabled. This is why it started working.

Went back to the standard Firefox 3.6.10 and disabled my add-ons one by one - Loaded up the ISPConfig after each one - No changes until I disabled "Google's - Page Speed 1.9".